1. Field of the Invention
The invention relates generally to an impulse combustion cleaning system. More specifically, the invention relates to an eductor shield around the downstream end of a detonation chamber to increase the effectiveness of an impulse cleaning system.
2. Discussion of Prior Art
Various devices and systems that have a flow that contains particulate matter may require cleaning after some period of use. Some examples of such devices/systems include industrial boilers, gas to air heat exchangers, and other types of heat exchangers used in processing/manufacture of product such as cement. Focusing for the moment on the one example of industrial boilers, such boilers operate by using a heat source to create steam from water or another working fluid, which can then be used to drive a turbine in order to supply power. The heat source may be a combustor that burns a fuel in order to generate heat, which is then transferred into the working fluid via a heat exchange. Burning the fuel may generate residues that can be left behind on the surface of the combustor or heat exchanger. Such buildups of soot, ash, slag, or dust on heat exchanger surfaces can inhibit the transfer of heat and therefore decrease the efficiency of the system. Periodic removal of such built-up deposits maintains the efficiency of such boiler systems.
Pressurized steam, water jets, acoustic waves, and mechanical hammering have been used to remove built-up deposits. These systems can be costly to maintain and the effectiveness of these systems varies. Pressurized steam, water jets, and mechanical hammering in many instances damage the heat transfer surface.
A supersonic combustion or impulse cleaning system has recently been used in an attempt to remove built-up deposits. Supersonic combustion events create strong impulse waves that remove the build-up deposits and accumulated debris from the heat exchanger surfaces. A shock wave is very effective in fluidizing a dust buildup. Improving the effective cleaning area and the flushing action of a shock wave by a single device is a continuing goal. Therefore, there is a need for development of effective and reliable impulse cleaning systems having an improved cleaning area and flushing action.